Genes of cell growth factor and growth factor receptors are called proto-oncogene and play important roles in behavior of human tumors including breast cancer (Arronson et al., Science Vol.254, pp.1141-1153, 1991). HER2 (Human EGF Receptor-2 genes having homology with the receptor of epidermal growth factor EGF are those of transmembrane receptor glycoprotein, and this receptor has tyrosine kinase activity (Akiyama et al., Science Vol.232, pp.1644-1656, 1986). HER2 is observed in human breast cancer and ovarian cancer (Slamon et al., Science, Vol.244, pp.707-712, 1989), which is further observed in prostate cancer (Lyne et al., Proceedings of American Association for Cancer Research Vol.37, p.243, 1996) or gastric cancer (Yonemura et al., Cancer Research Vol.51, p.1034, 1991). Further, the substrate of HER2-tyrosine kinase is observed in 90% of pancreatic cancers. Transgenic mice carrying HER2 gene develop mammary cancers as they grow (Guy et al., Proceedings of National Academy of Science U.S.A., Vol.89, pp.10578-10582, 1992).
It is disclosed that antibodies specific for HER2 suppress in vitro proliferation of tumor cells (Mckenzie et al. Oncogene Vol.4, pp.543-548, 1989) and humanized monoclonal antibody demonstrated prospective results in the clinical tests of patients suffering from breast cancer (Baselga et al., Journal of Clinical Oncology, Vol.14, pp.737-747, 1996).
These antibodies hinder the binding of growth factor with HER2 receptor and inhibit activation of tyrosine kinase. As the result, since it was shown that the advance of breast cancer was suppressed, it was shown that the drug directly inhibiting tyrosine kinase of HER2 was possibly effective as a medicine for the therapy of breast cancer (Hayes, Journal of Clinical Oncology, Vol.14, pp.697-699, 1996).
While several low molecular weight compounds inhibiting receptor-type tyrosine kinase containing HER2 have been reported, most of them are styrene-like compounds analogous to tyrosine itself having hydroxylated aromatic ring. For example, erbstatin inhibits proliferation of human epidermal carcinoma cell line A431 (Journal of Antibiotics, Vol.39, p.170, 1986), and it is reported that tyrphostin has antitumor activity in vivoon nude mice bearing the well-characterized human squamous cell carcinoma MH-85 (Cancer Research, Vol.51, p.4430, 1991). And, it it reported that sulfonylbenzoyl-nitrostyrene derivatives have antitumor activities in vivo in nude mice carrying A431 cell line. Further, it has been known that indole derivatives inhibit EGF receptor type tyrosine kinase and inhibit in vivo the growth of A431 cell line (International Application No. PCT/US93/7272, Japanese Patent Application under PCT laid-open under Kohyo No.Toku-Hyo-Hei 8-503450).
And, it has been known that triazole and diazole derivatives, although they are not tyrosine kinase inhibiting compounds, have the activity of inhibiting the signal transduction of cell proliferation due to growth factor (U.S. Pat. No. 5,482,954).